Wireless local area network (WLAN) stations, such as radio network cards and access points, typically provide access to a plurality of different physical layer data transmission rates (i.e., PHY rates). For example, WLAN stations designed in accordance with one of the 802.11x standard protocols may have physical layer data transmission rates at 1, 2, 6, 9, 12, 18, 24, 36, 48, and 54 megabits per second (Mbps). When such a station attempts to transmit a data frame or packet, it must decide which PHY rate to use. In general, higher PHY rates allow for higher throughput but at a reduced range while lower PHY rates allow for lower throughput at a greater range.
Some WLAN stations may implement a rate fallback algorithm for determining which PHY rate to use in a given circumstance. Typically, a rate fallback algorithm is implemented such that when the percentage of unsuccessful frame exchange sequences reaches an upper threshold, the transmitting station decides to decrease the PHY rate. Likewise, when the percentage of successful frame exchange sequences reaches a lower threshold, the transmitting station decides to increase the PHY rate. Because the distance between transmitting and receiving devices may vary within a wireless network, such a rate fallback algorithm allows the transmitter device to adapt the PHY rate to maximize throughput while maintaining an adequate wireless range.